CN109475893B

CN109475893B - System with nozzle unit and method for spraying inorganic clusters

Info

Publication number: CN109475893B
Application number: CN201780036259.3A
Authority: CN
Inventors: 马塔乌斯·海德尔; 克里斯蒂安·曼哈特
Original assignee: Refractory Intellectual Property GmbH and Co KG
Current assignee: Refractory Intellectual Property GmbH and Co KG
Priority date: 2016-07-28
Filing date: 2017-07-26
Publication date: 2022-03-18
Anticipated expiration: 2037-07-26
Also published as: CA3025870A1; WO2018019887A1; EP3490719A1; EP3490719B1; ES2834059T3; KR102490243B1; BR112019001377A2; CN109475893A; MX2019000454A; KR20190039181A; PL3490719T3; US20190168247A1; US11642685B2; BR112019001377B1

Abstract

A system for applying an inorganic coating to a surface (110), comprising: -a nozzle unit (50) having the following features: -a first end (51) having a first connection (11) for a first supply hose (10) for feeding a first component of a coating material; -a second end (52) for discharging the coating material from the nozzle unit (50); -a connection unit (60) for mixing and transporting the components of the coating from the first end (51) to the second end (52); -wherein the connection unit (60) comprises a mixing chamber (61) with at least one further connection (21, 31) for supplying a second component of the coating material; -wherein at least one electronic sensor (70) is mounted on the connection unit (60) to detect the oscillation amplitude (81) generated at the connection unit (60); -a data processing unit (80); -a comparison unit (90); -a control unit (100); wherein the control unit (100) generates a warning signal (101) when the control data (91) lie above a predetermined limit value and/or changes a volume flow (102) of at least one component of the coating material in dependence on the control data (91) generated by the comparison unit (90). And a method of applying an organic coating obtained by mixing a plurality of components in a nozzle unit (50).

Description

System with nozzle unit and method for spraying inorganic clusters

This application claims priority from a prior application with european patent office application No. EP16181666 at 28/7/2016, the contents of which are incorporated herein by reference in their entirety.

Technical Field

The present invention relates to a nozzle unit, a system, a method and the use of a nozzle unit for applying an inorganic coating, in particular an inorganic mass (sometimes also referred to as a mixture), onto a surface, such as the surface of a metallurgical vessel. The term inorganic mass especially includes ceramic masses, in particular refractory masses/monoliths, which have a consistency that can be continuously sprayed with a nozzle (nozzle unit). Inorganic mass is understood to mean in particular a mass consisting of at least 80% by weight or more particularly at least 95% by weight of inorganic material.

Background

Such refractory coatings (agglomerates) are used for the lining of industrial plants (furnaces, rotary kilns, shaft kilns, etc.), in particular metallurgical vessels (converters, ladles, electric arc furnaces, tundishes and other metal melting vessels), exposed to high temperatures (>1000 ℃).

For example, the inorganic coating is obtained by conveying a dry mixture (dry mass) to a nozzle unit and mixing it with other components (e.g. water, binder). The application is performed by spraying the resulting coating material in the surface direction through a nozzle unit (e.g., through a nozzle head). This process is known in the art as dry mix guniting.

In dry mix guniting, the operator typically adjusts the water (or liquid binder) level at the start of spraying in order to obtain the desired consistency of the coating, and thus optimum adhesion of the coating to the surface. Through visual control of the springback, the operator monitors the quality of the consistency throughout the spraying process.

By "consistency", inorganic coatings are generally understood the stiffness and processability (i.e. not the cured mass) of the freshly applied mass. The consistency may be subdivided into zones (similar to DIN 1045/EN 206 for concrete) falling within specific ranges of slump (slumping) and/or compaction.

A possible embodiment of a nozzle unit for a dry injection process is disclosed in DE 19819660 a 1.

In the context of automation and enhanced safety, the nozzle unit is attached to a manipulator, such as a robotic arm. Such application is described, for example, in EP 2255905 a1 or WO 03/081157 a 1. In this way, sensors measuring the inner surface of the metallurgical vessel, performing temperature measurements, or measuring the residual strength of the refractory lining may also be used.

In the case of fully or partially automated application of inorganic coatings, the coating must adhere consistently to the coated surface. This requires a uniform consistency of the coating.

Due to process fluctuations (e.g. flow rates changing over time, different application situations, e.g. "up" or "down", etc.), in practice the operator has to adapt the flow rates (volume flows) of the components of the coating medium repeatedly during spraying in order to achieve a uniform result. "volumetric flow rate" refers to the amount of a component (in volume or mass) flowing per unit time, for example, kilograms of mass per minute or liters of liquid per minute.

If there is a deviation between the respective actual consistency of the coating medium and the (optimized) target consistency (e.g. in case of a non-optimal ratio between the liquid component (e.g. water) relative to the dry component (e.g. refractory mass)), the following problems may arise:

if the amount of liquid component is too high, the porosity of the coating medium becomes too high, resulting in long drying times and poor ("running off") of the initial adhesion of the coating medium to the surface to be coated,

"flaking" is caused by the high vapour pressure in the still undried layer, which cannot escape through the already dried outer layer and cause the material to detach from the surface,

if the amount of liquid component is too low, this leads to dust formation and loss of fine particles (delamination of the components) and poor initial adhesion of the coating medium to the surface to be coated, i.e. increased recoating.

In order to record the quality of the results obtained for surface coatings, it may be important to provide a record of the coating, in particular to verify the uniform and proper consistency of the coating.

Disclosure of Invention

On this background, it is an object of the present invention to provide a nozzle unit, a system and a method which allow for continuous monitoring of the consistency (and thus the quality) of inorganic coatings, in particular fire-resistant inorganic coatings, during application (spraying).

According to the invention, this object is achieved by a system according to claim 1 and a method having the features according to claim 9. Advantageous developments, developments and variants are the object of the dependent claims. The advantages and improvements mentioned in connection with the method are similarly applicable to products/physical objects.

The core idea of the invention is based inter alia on the following findings: the structure-born sound (mechanical vibration) generated in the part of the nozzle unit, or the amplitude of the oscillations generated thereby and detectable on the surface of the nozzle unit, allows conclusions to be drawn about the consistency of the inorganic coating material located in the nozzle.

In the following, "oscillation amplitude" is understood as the time profile of the detected oscillation. Mathematically, this is a continuous function g (t) or its discrete value g (t) at a particular time_i)。

In the following, "frequency spectrum" is understood as a representation of the oscillation amplitude in the frequency domain in a particular time interval. These are therefore coefficients of oscillation (frequency amplitude values) which are composed of the oscillation amplitude within a certain time interval. The frequency amplitude value G (fj) of the respective frequency component is obtained from the frequency fj or a function (G (t, fj)) of their time progression.

In one aspect of the invention, this object is achieved by providing a system for applying an inorganic coating, in particular a refractory coating, to a surface, in particular a surface of a metallurgical vessel, comprising the following features:

the nozzle unit according to the invention has the following features:

a first end having a first connection for a first supply hose for supplying a first component of the coating material,

a second end for discharging the coating material from the nozzle unit,

a connection unit for mixing and transporting the components of the coating from the first end to the second end,

wherein the connection unit comprises a mixing chamber with at least one further connection for supplying a second component of the coating material,

and wherein at least one electronic sensor is mounted on the connection unit to receive the amplitude of the oscillation generated at the connection unit,

a data processing unit for acquiring oscillation amplitudes detected by the electronic sensors of the nozzle unit and calculating an actual spectrum or a target spectrum from the detected oscillation amplitudes,

a comparison unit for comparing the actual spectrum with a target spectrum for generating control data,

-a control unit for controlling the operation of the control unit,

wherein the control unit

-generating a warning signal if the control data is outside a defined range or above a predetermined limit value,

and/or:

-varying (changing) the volumetric flow rate of at least one component of the coating material in accordance with the control data generated by the comparison unit.

The data processing unit, the comparison unit, the control unit are to be understood as one or more devices for carrying out the respective method steps described below and, for this purpose, comprise discrete electronic components for processing signals or are implemented partly or wholly as computer programs in a computer.

The data processing unit is connected to the sensor of the nozzle unit and can perform the following method steps:

the signals of the sensor are continuously monitored (oscillation amplitude) and converted into a frequency spectrum (frequency amplitude).

The acquisition of the oscillation amplitude is preferably done by electronic means, for example by digitizing the electrical signal from the sensor and subsequently storing the digitized data digitally on a data carrier or in the memory of a computer.

The conversion (transformation) of the oscillation amplitude into frequency amplitude, i.e. the calculation (frequency transformation) of the frequency spectrum, is done, for example, by means of a fourier transformation or a fast fourier transformation.

The spectrum is calculated from the oscillation amplitude at a particular time interval. The time interval is in the range of 10 milliseconds to 5 seconds.

The detected oscillation amplitude can be predetermined (for example, at time t-0 or at a defined time t-t)_OPTWhere) calculates a target spectrum. In the presence of an optimal consistency, the oscillation amplitude is referred to as the "target signal"; in this case, the spectrum is referred to as a "target spectrum".

Can be carried out in real time (during operation, e.g. at time t) from the detected oscillation amplitude>0 or t>t_OPTWhere) the actual spectrum is calculated. In this case, the oscillation amplitude is referred to as "actual signal". In this case, the spectrum is referred to as "actual spectrum".

Discrete time value t as sensor₀、t₁、t₂Oscillation amplitude g (g (t) of the function of (c)₀)，g(t₁)，g(t₂) .... values: current or voltage/potential) is converted by transformation as a discrete frequency f_jFrequency amplitude value G of the function of. Applying a transform (FT for frequency transform) to a particular time interval (e.g., at time t)_jWherein i ═ i₀...i₁) Where at time t ═ t_i1(G(t_i1，f_j) A spectrum is obtained.

G(t_i1，f_j)＝FT(g(t_i0)，...，g(t_i1))

The frequency transformation FT is preferably a transformation that calculates the power spectrum from harmonic oscillations of the signal function f (harmonic power in the signal), i.e.:

FT(f)＝X(f)X*(f)＝|X(f)|²

wherein x (f) FFT (g (t)_i0)，...，g(t_i1) Is the so-called fast fourier transform and X (f) is the complex conjugate of X (f).

The comparison unit may perform the following processing steps:

the comparison unit compares the two frequency spectra, in particular the actual frequency spectrum, with the target frequency spectrum.

For this purpose, for example by being in a defined frequency range

The frequency amplitude values G are summed to obtain frequency components from the frequency spectrum. In particular, at least one actual frequency component is determined from the actual frequency spectrum and/or at least one target frequency component is determined from the target frequency spectrum by summing corresponding frequency amplitude values over a specific frequency range.

Preferably, at least one frequency component is calculated in the fj range from (a) 3000 hz to (b) 9300 hz from the actual and target frequency spectrum, respectively

Within this range a particularly good dependency of the consistency of the liquid/solid phase mixture is achieved.

Alternatively (additionally), frequency components

May be calculated as a moving average (sliding mean) for smoothing the signal. Thus, for example,

the length of the time interval over which the moving average can be calculated is selected based on the quality of the data.

The calculation of the moving average has the effect that short-term or high-frequency disturbances have no influence on the injection result.

Comparison unit generalBy averaging the currently calculated spectrum (actual spectrum) or its calculated frequency components (e.g. average amplitude at time t)

) Frequency components calculated from the reference spectrum (target reference spectrum) or the reference spectrum (for example, average amplitude at time t-0)

) A comparison is made to calculate the control data. This reference/target spectrum or its frequency components (target frequency components) have been stored in advance, for example, in a comparison unit.

Control data was generated by comparing the two spectra.

Specifically, the control data s (t) may be generated by a weighted sum of deviations (differences) between the actual frequency components and the target frequency components.

This can be done, for example, by linear summation and/or by a weighting factor a_nThe sum of the squares of the differences of each or all target/actual frequency components, respectively, is achieved:

or, alternatively, can also be formed by the quotient of the target and actual frequency components and by a linear summation and/or a square summation of the quotient of the individual or all target/actual frequency components, in each case using the weighting factor a_n：

The weighting factors may be obtained through empirical studies, through mathematical models that simulate calculations, or through computer-aided learning (e.g., in the manner of a neural network).

The weighting factor can also be obtained by varying the volume flow of the coating components.

The control data s (t) is generated by the comparison unit and is available to the control unit.

For example, the control unit may issue a warning signal if the control data is outside a defined range (e.g. if s (t) exceeds some predefined limit value). The warning signal may be acoustic (emission of sound), optical (e.g. by a warning light or an on-screen display). The warning signal can also be fed to another control unit, in particular in the sense of an emergency shut-down, which can lead to the end of the injection process.

The control unit may vary the volumetric flow of at least one component of the coating material, for example in accordance with the control data s (t), wherein at least one electrically controlled valve is provided in the control unit.

Preferably, the control is performed by changing the volumetric flow rate of the second component by adjusting the volumetric flow rate of the second component in accordance with the control data s (t). This is used for a fast and accurate adjustment of the consistency, since the flow rate of the non-solid (e.g. liquid) component can be adjusted fast and accurately.

The electrically controlled valve for changing the volume flow of the second component is, for example, an electrically controllable needle valve, since in this way the most precise adjustment is achieved.

Thus, the volume flow of water can be reduced by simple control according to the control data (e.g. S >0), or increased by adjusting the electrically controlled valve (e.g. S < 0).

Additionally or alternatively, the adjustment may be achieved by changing the volumetric flow rate of the first component. This can be achieved by adjusting the delivery rate of the controllable delivery pump, wherein a change in the delivery rate of the first component is achieved. This enables a simple and robust adjustment of the consistency and thus of the long-lasting device, since here a reliable adjustment can be achieved without additional components (valves or the like) or even in the event of failure of these components.

Thus, the volumetric flow rate of the dry mass can be increased by simple adjustment according to the control data (e.g. S >0) or decreased by controlling the delivery pump (e.g. S < 0).

The most consistent results were obtained using a proportional-integral-derivative controller (PID controller).

The control data may be stored for subsequent quality control.

The system may for example comprise a manipulator which is mechanically connected to the nozzle unit such that it allows the application of surfaces which are difficult to access, such as the inner surfaces of metallurgical vessels. For applications in the steel industry, especially due to the high temperature of such surfaces, the operator must keep a very large distance or in narrow or dangerous areas, often such surfaces are difficult to access.

The connection of the nozzle unit and the manipulator may preferably be realized by a rotatable connection.

The manipulator may be mounted in its movable and/or rotatable manner on a first end on the ground or on another fixed equipment (e.g., a work platform of a ladle maintenance equipment).

In particular, the manipulator may be designed in the manner of a robotic arm and include various kinematics known in the robotics.

The nozzle unit may be part of a manipulator as a whole or in parts. For example, the conduit of the connection unit may be an arm of the manipulator.

The system according to the invention may further comprise additional sensors, for example for temperature measurement or for optical inspection of the surface to be coated.

The control data may be used to control the manipulator. For example, it can be provided that the forward movement of the manipulator is stopped or slowed down if the control data is above a predetermined limit value. This is used for automatic error-free application of the coating.

Alternatively, the manipulator may be a manually operated lance or extension tube.

The nozzle unit according to the invention for applying an inorganic coating, in particular an inorganic refractory coating, to a surface, in particular a metallurgical vessel surface, has at least the following features:

a second end for discharging the coating material from the nozzle unit,

wherein the connection unit comprises a mixing chamber having at least one connection for supplying the second component of the coating material,

an electronic sensor mounted on the connection unit for detecting the amplitude of the oscillation generated at the connection unit.

The inorganic coating is preferably a refractory inorganic group. In such refractory inorganic masses (refractory materials), the precise adjustment of the liquid components is particularly important when applied by the dry-mix shotcrete method, and in addition to those problems already mentioned in the case of deviations from the target consistency, the following problems arise:

the exact water content is very important for conventional ceramic bonding in refractory materials (compared to hydraulic bonding in concrete), since even minor deviations from the optimum water content lead to a reduction in the quality of the resulting coating,

high safety requirements in the field of refractory application,

in the case of refractory materials, only the optimum "minimum" amount of water can be used, since too high a water content can lead to destruction of the coating at high temperatures,

generally, no liquefier is used for the refractory material, and therefore it is much more difficult to adjust the optimum consistency (for example purely by adding water) in the case of refractory materials.

The first supply hose (delivery hose) typically provides the dry mass as the first component via the first connection of the nozzle unit. This is typically accomplished by introducing the dry mass into an air stream.

The first component is designed for coating metallurgical vessels, such as converters, ladles, electric arc furnaces, tundishes. The first component is typically a solid, such as a dry basic refractory mass. For example, it may be a magnesium oxide cluster.

Conventional particles are in the range of 0 to 5 mm, in particular in the range of 0 to 3 mm.

In the following, the end is in particular the free end of the component.

The connection unit may be designed such that the connection unit may comprise a substantially step-free and kink-free path between the first end of the nozzle unit and the second end of the nozzle unit. In other words, there is no discontinuous change in the flow characteristics of the first component of the coating between the first end and the second end. This avoids clogging of the nozzle unit and avoids increased wear caused by wear in the nozzle unit.

The nozzle unit is designed for a standard delivery rate of the first component in the range of 50-350 kg/min.

The connection unit comprises at least one mixing chamber in which the first component is mixed with at least one second component.

For this purpose, the second component is fed to the mixing chamber via a second connection via a second supply hose.

The second component is typically a non-solid component, i.e. free of solid matter. The second component may be a liquid component, such as water, or alternatively a binder in an aqueous solution, such as a sol, in particular a sol of dispersed silica. The pressure of the second component may be in the range of 1 bar to 40 bar. The typical amount of the second component is 2-15% by weight based on the first component.

There may be additional connections to the mixing chamber; the third component may be fed to the mixing chamber via a third connection via a third supply hose. The third component may be, for example, a gaseous component, such as compressed air.

The pressure of the third component may be in the range of 1 bar to 40 bar. This allows the second component to mix with the third component in the antechamber (i.e., compressed air may then be used to disperse the water in the finest droplets, for example). Improved mixing of all three components is achieved by the principle of a two-substance nozzle (so-called binary nozzle).

At least one electronic sensor is mounted on the connection unit, which can detect the amplitude of the oscillation occurring at the connection unit.

The sensor is preferably mounted on an outer surface of the connection unit and is connected to the connection unit in a form-fitting manner.

The sensor may be mounted on the mixing chamber of the nozzle unit. An error or change in the mixing process is detected in this region (e.g., clogging of the nozzle by the second component, wear in the mixing chamber, etc.).

When a sensor mounted on the mixing chamber of the two-substance nozzle is used to mix the first component of the basic refractory mass with water as the second component and compressed air as the third component, errors or variations in the mixing process can be detected directly (i.e. very quickly), so that very small fluctuations in the application quality of the coating on the surface can be detected.

The connection unit may further include a pipe. The pipe is connected at its first end to the mixing chamber of the connection unit, so that the components of the coating medium are brought together in the mixing chamber and are already premixed when fed into the pipe. The task of this pipe is to further improve the mixing (homogeneity) of the components and to reduce and largely laminarize turbulence (present in the mixing chamber). In particular, the conduit may be in the form of a straight or curved hollow cylinder. The length of the pipe is preferably in the range of 5 cm to 10 m.

In particular, long pipes with a length of more than 5 meters can be used to ensure mixing in the low-temperature region, since in this case the mixing chamber is at a distance from the hot surface to be coated that is at least equal to the length of the pipe.

The connection unit may further include a nozzle head. The task of the nozzle head is to form a coating medium flow. The nozzle head is connected at its first end to the mixing chamber of the connection unit or to the second end of the conduit, so that the components of the coating medium which have been premixed in the mixing chamber are guided to the nozzle head (possibly via the conduit). In particular, the nozzle head may have a varying, for example narrowing, cross-section. In this embodiment the nozzle head or the second (open) end of the nozzle head forms the second end of the nozzle unit.

The coating medium leaves the spray nozzle unit via the second end of the spray nozzle unit in the direction of the surface to be coated.

The sensor is preferably mounted on the pipe. In other words, the sensor is in form-fitting connection with the tube shape, wherein the connection is such that normal oscillations of the surface of the tube can be detected by the sensor.

Mounting the sensor on the pipeline can achieve the best signal quality (i.e. lowest fluctuation). This is due to the fact that the flow conditions in the pipe are closest to laminar flow, whereas the flow conditions in the mixing chamber or nozzle head are rather turbulent in nature.

In combination with long pipes having a length of more than 5 meters, there is the additional advantage that the temperature is significantly reduced when used in a metallurgical vessel in the region of the mixing chamber or at the pipe end of the pipe adjacent to the mixing chamber, compared to when used in front of the nozzle unit.

The mounting position of the sensor on the pipe is in the range up to 1 meter away from the end of the pipe adjoining the mixing chamber, or in the range up to 20 times, preferably up to 10 times, the distance of the pipe inner diameter (the inner diameter of the pipe preferably lies in the range of 5 to 15 cm), which will show advantageous results. Also in this range the lowest temperature and good flow conditions occur.

It is particularly preferred that the mounting position of the sensor on the pipe is in the range of 0.5 to 1 meter away from the end of the pipe adjoining the mixing chamber, or in the range of 5 to 20 times, preferably 5 to 10 times the inner diameter of the pipe. A uniform consistency is also seen in this range, while the mixing motion (e.g. near the mixing chamber) does not generate noise.

Therefore, the sensor needs to be less protected against temperature radiation while achieving a longer lifetime of the sensor.

In one embodiment, the plurality of sensors are mounted at the same mounting location on the pipe, but distributed over the circumference of the pipe. In other words, a plurality of sensors are mounted on the surface of the pipe, with each sensor being equidistant from the end of the pipe adjacent the mixing chamber. Preferably, three sensors are provided in this embodiment, wherein preferably the three sensors are evenly distributed over the circumference of the tube, i.e. they form an angle of 120 ° with respect to each other at the center (axis) of the tube. This allows for determining inhomogeneities in the coating, since the acoustic information is obtained from multiple sides.

In one embodiment, the connection unit comprises a mixing chamber, a pipe and a nozzle head. The components of the inorganic coating are first brought together and premixed in a mixing chamber, then further homogenized in a pipe, and then the fluid is made to flow laminar and pass into a nozzle head. The inorganic mass premixed by means of the nozzle head is guided onto the surface to be coated and leaves the nozzle unit through the nozzle head.

The sensor detects the amplitude of the oscillation generated at the connection unit, i.e. the structure-born sound. This is done according to the acceleration measurement principle. In particular, the oscillatory deflection normal to the surface of the connection unit is recorded. Thus, the sensor typically provides acceleration values normal to the surface of the connection unit in the form of a series of electrical values (power or potential) as a function of time.

With this method, the sound influence from the environment is detected only to a very limited extent and no interference is generated.

The sensor is designed as an oscillating sensor and is preferably selected from the group consisting of: the sensor comprises a laser vibrometer, a piezoelectric accelerometer, a piezoresistive sensor, a strain gauge, a capacitance acceleration sensor and a magnetic resistance acceleration sensor. By using one of these acceleration sensors, the influence of sound from the environment (e.g., secondary noise) can be largely excluded.

Conventional sound sensors, such as microphones, are disadvantageous or even unsuitable because they pick up much background noise.

The sensor is preferably a piezoelectric acceleration sensor, which is connected to a part of the connection unit by a rigid connection in a form-fitting manner.

By using the piezoelectric acceleration sensor, environmental influences (such as secondary noise) can be largely eliminated, and at the same time, high reproducibility and long life of the nozzle unit can be achieved.

For example, the sensor may be integrated into a clamp (holder) that is part of the connection unit. This allows easy replaceability.

The components of the nozzle unit are preferably constructed of a wear resistant material. Thus, in particular, the connection unit (i.e. the mixing chamber, the pipe and the nozzle head) may be made of steel.

In a further aspect of the invention, this object is achieved by providing a method for applying an inorganic coating to a surface, in particular a surface of a metallurgical vessel, which inorganic coating is obtained by mixing several components in a nozzle unit according to the invention, comprising the steps of:

measuring the oscillation amplitude detected by the electronic sensor of the nozzle unit during mixing and delivery of the components of the coating material by the connection unit of the nozzle unit,

-calculating an actual frequency spectrum from the measured oscillation amplitude,

-generating control data by comparing the actual spectrum with a stored target spectrum,

and

-generating a warning signal when the control data is outside the defined range,

and/or

-changing the volume flow of the coating composition in dependence on the control data generated by the comparison unit.

The method is used to check the consistency of an inorganic coating obtained by mixing several components in a nozzle unit according to the invention.

The method is in one aspect performed using a nozzle unit according to the invention, wherein the nozzle unit comprises for example the following features:

a second end for discharging the coating material from the nozzle unit,

wherein the connection unit has a mixing chamber with at least one further connection for supplying a second component of the coating material,

and at least one electronic sensor is mounted on the connection unit for detecting the amplitude of the oscillations generated at the connection unit.

The method is therefore carried out using a nozzle unit according to the invention, wherein a dry, in particular fire-resistant, first component of the coating is preferably supplied to the nozzle unit from a first supply hose, and a liquid, in particular aqueous, second component of the coating is preferably supplied to the nozzle unit from the first supply hose. The supplied components are mixed in the connection unit of the nozzle unit. An electronic sensor mounted on the connection unit detects an amplitude of oscillation generated at the connection unit. The mixed paint is guided to the second end of the nozzle unit and leaves the nozzle unit in the direction of the surface to be coated of the nozzle unit. The mixed coating impinges on the surface to be coated, dries, and then forms a surface coating.

The Dry, in particular fire-resistant, first component of the coating is provided, for example, by a suitable machine, for example, by what is known as Gunite or Dry-Gunning (Dry-Gunning) machine (also known as RHI Ankerjet, for example, of the type aj10A.. 40A).

In principle, a dry, in particular fire-resistant, first component is provided in a storage container of such a suitable machine and is then conveyed to the first connection of the nozzle unit by means of a gas flow generated in such a machine or by means of an external compressor or the like via a first supply hose. The pressure in the first supply hose may be in the range of 0.5 to 8 bar.

The liquid, in particular aqueous, second component of the coating material is conveyed by a suitable pump via a second supply hose to the second connection of the nozzle unit. The pressure in the second supply hose may be in the range of 1.5 to 8.5 bar. The pressure in the second supply hose is preferably about 0.5 bar or about 0.5 bar higher than the pressure in the first supply hose.

During the mixing and delivery of the components of the coating material, the oscillation amplitude detected by the electronic sensor of the nozzle unit is continuously detected (i.e. at the current actual consistency).

The target spectrum may be obtained in advance by:

setting/defining a target consistency of the coating by varying the volumetric flow of the coating components (until a consistency of good quality is selected),

measuring the oscillation amplitude by an electronic sensor of the nozzle unit while the coating is mixed and conveyed with the target consistency by the connection unit of the nozzle unit,

-calculating a target spectrum from the measured oscillation amplitude,

storing the target spectrum (e.g. in computer memory).

Another aspect of the invention relates to the use of a nozzle unit according to the invention for applying an inorganic coating, in particular an inorganic mass, onto a surface, for example onto a surface of a metallurgical vessel.

Another aspect of the invention relates to the use of the system according to the invention for applying an inorganic coating, in particular an inorganic mass, to a surface, for example to a surface of a metallurgical vessel.

Drawings

Exemplary embodiments of the invention are explained in more detail by way of illustration:

figure 1 shows a schematic view of a nozzle unit according to the invention,

figure 2 shows a schematic sequence of the method according to the invention,

fig. 3a and 3b show example diagrams of the quotient of the actual frequency component and the target frequency component.

Detailed Description

Exemplary embodiment 1:

fig. 1 shows a first supply hose (conveying hose) 10, which conveys a basic mass (Ankerjet NP12, basic mass, 0-3 mm prilling band, highly fire-resistant) such that the latter passes through a first end 51 of the nozzle unit 50 to the mixing chamber 61 via a first connection 11. The water enters the mixing chamber 61 through the second supply hose 20 via the second connection 21. The compressed air reaches the mixing chamber 61 via the third supply hose 30 via the third connection 31. The coating is formed in the mixing chamber 61 from the components of the basic mass of the Ankerjet NP12, wherein water and air are mixed and transported through a pipe 62 (length: 2 meters) into the nozzle head 63 and then out of the nozzle unit 50 via the second end 52 and from there to the surface 110 to be coated. The nozzle unit 50 is made of steel. The piezoelectric sensor 70 is connected to the pipe 62 with a form fit, is located at the center of the pipe 62 (i.e. the end of the pipe adjacent to the mixing chamber 61 is 1 meter away, or 10 times the pipe diameter, which is 10 cm), and detects the oscillation amplitude 81 occurring in the pipe 62, which is acquired by the data processing unit 80. The data processing unit 80 is connected to the comparison unit 90 and controls, via the control data 91, the control unit 100 to regulate the throughflow/volume flow 102 of the components by means of a controllable delivery pump (100a) or controllable electrovalves (100b, 100c) for the coating material.

Fig. 2 shows a piezoelectric sensor 70 (here: an ICP accelerometer, model 352C33) mounted on the tube 62 of the connection unit 60, which provides an analogue data signal to the data processing unit 80. The data processing unit 80 in this example embodiment is a computer using LabView software. The analog data signal is first digitized (16 bits, 51400 hz) to obtain a time-dependent oscillation amplitude 81. This is continuously converted into the frequency spectrum 82 in an FFT (fast fourier transform) module, thereby obtaining frequency amplitude values 93 (within a time interval of 250 milliseconds of oscillation amplitude). Three frequency components 92 are continuously calculated from frequency magnitude value 93 by averaging frequency magnitude value 93, frequency magnitude value 93 being between 1-2999 hertz

3000 and 9300 Hz

And 9301-

Within the range of (1). Calculating these values

And

as a moving average with a time interval of 15 seconds for further processing. Then, the control data 91 is calculated from the frequency amplitude value 93 and forwarded to the control unit 100. When the maximum value of the control data 91 is exceeded, the control unit outputs a warning signal 101 and adjusts the volume flow 102.

The nozzle unit 50 in this exemplary embodiment is a binary nozzle. The dry mass (Ankerjet NP12) is conveyed via a first supply hose 10 to the first connection 11 of the nozzle unit 50 by means of compressed air (conveying air) supplied by a compressor (pressure 6 bar; mass is introduced into the air stream by means of an "Ankerjet" machine, wherein the pressure in the air stream is 0.5 bar and the (air) flow rate is about 190 cubic meters per hour). Water is supplied directly from the drinking water line to the second connection 21 via the second supply hose 20 by the water pump WK155 at a pressure of about 1.5 bar. The volume of water is set by means of an electrically controlled valve 100b (measurement of the exact volume flow of water is carried out by means of a flow meter from Krohne DN 50, PN-40 bar, Q-0-50 cubic meters per hour, output I-4-20 milliamperes). Compressed air (atomizing air) is supplied to the third connection 31 of the nozzle unit 50 via the third supply hose 30 at a pressure of 1.5 bar and 50 cubic meters per hour (supplied via a screw compressor of the company KAESER, which is model BSD 81T (11.0 bar 400V)). The nozzle unit 50 is horizontally aligned in the direction of the surface 110 to be coated. The surface 110 is aligned at a distance of 3 meters from the second end (52) of the nozzle unit 50 and is substantially normal to the axis of the nozzle unit 50.

Table 1 shows the test results.

Table 1: test list

optimal// () reference value

In test No. 1, the flow rate of the basic mass was determined to be about 120 kg/min (volume flow rate). Water (water content in the mass of 0.050 litres per kilogram of water) was added at 6 litres per minute (volume flow). It is judged to be too dry because some dust formation occurs and a large mass bounces off the surface 110 to be coated.

In test No. 2, the amount of water was increased to 9.2 l/min (water content 0.077 l/kg; mass: 120 kg/min). The results were evaluated as optimal because most of the mass adhered to the surface to be coated 110, no dust formation occurred, and the mass did not run off. According to the oscillation amplitude 81 obtained at this optimum water contentAnd three target frequency components 92 calculated therefrom

And

a target spectrum 82 is calculated. These obtained values are used as references (target frequency components 92) for the remaining examples.

In test No. 3, the amount of water was increased to 13 liters/minute (water content 0.18 liters/kg, mass: 120 kg/minute). The result is judged to be too wet because the mass is partially lost from the surface 110.

In test No. 4, the mass was added at 75 kg/min from an amount of water added at 6 liters/min (water content 0.080, mass: 75 kg/min). The results were evaluated as optimal because most of the mass adhered to the surface to be coated 110, no dust formation occurred, and the mass did not run off. However, only a smaller volume flow is used compared to the results of test 2.

In test No. 5, the mass was added at 100 kg/min from an amount of water added at 6L/min (water content 0.060, mass: 100 kg/min). The result was judged to be too dry, since some dust formation occurred and many lumps bounced off the surface to be coated.

Target frequency component 92 to be obtained from test number 2

And

comparison with values obtained from other tests (actual frequency component 92)

And

) In the form of quotient (i.e. in the form of

And

) Shown schematically).

FIG. 3a shows the quotient as a function of the water content

As a quotient of water added in litres/minute and mass supplied in kilograms/minute. At an optimum consistency, at an overall low volume flow (mass M75 kg/min, water W6 l/min)

) And high volume flow (mass M120 kg/min, water W9.2 l/min)

Signal of (2) in between

A large difference is detected. Thus, this value allows monitoring of the constant volumetric flow rate of the dried mass (Ankerjet NP12) in this exemplary embodiment. Here, the control data 91 may be formed

When | S (t) & gtneutral>At 10%, a warning signal 101 is issued by outputting a message on the screen.

FIG. 3b shows the quotient as a function of the water content

The process of (1). Business support

Showing a good correlation with water content, independent of the volumetric flow rate of the dried mass. Thus, this value can be used to control the data 91 by setting it

To control the volumetric flow rate 102 of the water. When S is<At 0, the volumetric flow rate of water is reduced by one unit (e.g., 0.1 liters/minute) by means of the electrically controlled valve 100 b. When S is>At 0, the volumetric flow rate 102 of water is increased by one unit. By this adjustment, a uniform good consistency is obtained over a long application time.

Quotient as a function of water content

Is similar in nature to that in fig. 3b

And therefore similar conclusions apply here.

Reference numerals and factor lists

10 first supply hose (delivery hose)

11 first connecting piece

20 second supply hose

21 second connecting piece

30 third supply hose

31 third connecting piece

50 nozzle unit

51 first end of nozzle unit

52 second end of nozzle unit

60 connecting unit

61 mixing chamber

62 pipeline

63 nozzle head

70 sensor

80 data processing unit

81 amplitude of oscillation

82 spectrum

90 comparison unit

91 control data

92 frequency component

93 value of frequency amplitude

100 control unit

100a controllable delivery pump

100b electric control valve

100c electric control valve

101 warning signal

102 volume flow rate

110 surface to be coated

Claims

1. A system for applying an inorganic coating to a surface (110), comprising:

-a nozzle unit (50) comprising the following features:

-a first end (51) having a first connection (11) for a first supply hose (10) for supplying a first component of a coating material,

a second end (52) for discharging the coating material from the nozzle unit (50),

-a connection unit (60) for mixing and transporting components of the coating material from the first end (51) to the second end (52), wherein the connection unit (60) between the first end (51) and the second end (52) of the nozzle unit constitutes a substantially step-free and kink-free path,

-wherein the connection unit (60) comprises a mixing chamber (61) with at least one further connection (21, 31) for supplying a second component of the coating material,

-and wherein at least one electronic sensor (70) is mounted on the connection unit (60) to detect an oscillation amplitude (81) generated at the connection unit (60),

a data processing unit (80) for acquiring oscillation amplitudes (81) detected by an electronic sensor (70) of the nozzle unit (50) and for calculating an actual spectrum (82) or a target spectrum (82) from the detected oscillation amplitudes (81),

a comparison unit (90) for comparing the actual spectrum (82) with the target spectrum (82) and generating control data (91),

-a control unit (100),

wherein the control unit (100)

-generating a warning signal (101) when said control data (91) is outside a defined range, and/or

-varying a volumetric flow rate (102) of at least one component of the coating depending on the control data (91) generated by the comparison unit (90).

2. The system of claim 1, wherein the first and second sensors are disposed in a common housing,

it is characterized in that the preparation method is characterized in that,

the comparison unit (90) determines an actual frequency component (92) and/or a target frequency component (92) by summing corresponding frequency amplitude values (93) from the actual frequency spectrum (82) and/or the target frequency spectrum (82) within a defined frequency range.

3. The system of claim 2, wherein the first and second sensors are arranged in a single package,

it is characterized in that the preparation method is characterized in that,

the comparison unit (90) generates control data (91) from a weighted sum of deviations or quotients between the actual frequency components (92) and the target frequency components (92).

4. The system according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

the system further comprises a manipulator mechanically connected to the nozzle unit to allow application to a surface (110) that is difficult to access.

5. The system according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

the connection unit (60) comprises a pipe (62) connected to the mixing chamber (61), wherein the sensor (70) is mounted on the pipe (62).

6. The system according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

the sensor (70) is a piezoelectric acceleration sensor.

7. The system according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

the sensor (70) is integrated in a clamp surrounding the connection unit (60).

8. The system of claim 4, wherein the first and second sensors are arranged in a single package,

it is characterized in that the preparation method is characterized in that,

the inaccessible surface (110) is an inner surface of a metallurgical vessel.

9. Method for applying an inorganic coating obtained by mixing a plurality of components in a nozzle unit (50) having at least one electronic sensor (70) to a surface (110), comprising the steps of:

-measuring the oscillation amplitude (81) detected by an electronic sensor (70) of the nozzle unit (50) during mixing and conveying of the inorganic paint by means of a connection unit (60) of the nozzle unit (50)

-calculating an actual frequency spectrum (82) from the measured oscillation amplitude (81),

-generating control data (91) by comparing the actual spectrum (82) with a stored target spectrum (82), and

-generating a warning signal (101) when the control data (91) is outside a defined range,

and/or

-changing the volumetric flow rate (102) of at least one component of the coating material in dependence on control data (91) generated by a comparison unit (90),

the nozzle unit (50) comprises the following features:

-a first end (51) having a first connection (11) for a first supply hose (10) for supplying a first component of the coating material,

-and wherein at least one electronic sensor (70) is mounted on the connection unit (60) to detect the oscillation amplitude (81) generated at the connection unit (60).

10. The method of claim 9, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

the calculation of the actual frequency component (92) or the target frequency component (92) is performed by summing frequency amplitude values (93) over a specific frequency range of the actual frequency spectrum (82) or the target frequency spectrum (82) to generate control data (91).

11. The method according to claim 9 or 10,

it is characterized in that the preparation method is characterized in that,

at least one frequency component is calculated (92) in the frequency range of 3000-.

12. The method according to claim 9 or 10,

it is characterized in that the preparation method is characterized in that,

the control data (91) is generated by a weighted sum of deviations or quotients between the actual frequency components (92) and the target frequency components (92).

13. The method according to claim 9 or 10,

it is characterized in that the preparation method is characterized in that,

obtaining a target spectrum (82) by:

-setting a target consistency of the coating by changing volumetric flow rates (102) of components of the coating,

-measuring the oscillation amplitude (81) detected by the electronic sensor (70) of the nozzle unit (50) while the coating is mixed and delivered at a target consistency by the connection unit (60) of the nozzle unit,

-calculating a target spectrum (82) from the measured oscillation amplitude (81),

-storing the target spectrum (82).

14. The method of claim 9, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

further, the air conditioner is provided with a fan,

-providing a dry first component of the coating material to the nozzle unit (50) by the first supply hose (10) and a second component of the liquid of the coating material to the nozzle unit (50) by a second supply hose (20), wherein the first and second components of the coating material are mixed in the nozzle unit (50), and

-directing the mixed coating material to the second end (52) of the nozzle unit (50) where it leaves the nozzle unit (50) in the direction of the surface (110) to be coated;

-then projecting said mixed coating on said surface to be coated (110) and forming a coating of said surface (110) after drying.

15. The method of claim 14, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

the dry first component of the coating is a dry fire resistant first component.

16. The method of claim 14, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

the second component of the liquid of the coating is an aqueous second component.